diff --git a/packages/zai-cli/src/commands/code.ts b/packages/zai-cli/src/commands/code.ts
index 9913950..7d27b95 100644
--- a/packages/zai-cli/src/commands/code.ts
+++ b/packages/zai-cli/src/commands/code.ts
@@ -91,7 +91,7 @@ Options:
 
 Examples:
   zai-cli code run ./chain.ts
-  zai-cli code eval "const r = await zai.search.webSearchPrime({search_query:'ZAI'}); return r;"
+  zai-cli code eval "const r = await zai.search.web_search_prime({search_query:'ZAI'}); return r;"
   zai-cli code interfaces
   zai-cli code prompt
 `.trim();
diff --git a/packages/zai-cli/src/commands/tools.ts b/packages/zai-cli/src/commands/tools.ts
index e8854b4..7b410bb 100644
--- a/packages/zai-cli/src/commands/tools.ts
+++ b/packages/zai-cli/src/commands/tools.ts
@@ -194,7 +194,7 @@ Options:
   --no-vision       Skip vision MCP server (faster startup)
 
 Examples:
-  zai-cli call zai.search.webSearchPrime --json '{"search_query":"LLM tools"}'
+  zai-cli call zai.search.web_search_prime --json '{"search_query":"LLM tools"}'
   zai-cli call zai.reader.webReader --file ./args.json
   echo '{"repo_name":"owner/repo"}' | zai-cli call zai.zread.get_repo_structure --stdin
 `.trim();
diff --git a/packages/zai-cli/src/lib/mcp-client.ts b/packages/zai-cli/src/lib/mcp-client.ts
index 49dbd4b..9d3bd3c 100644
--- a/packages/zai-cli/src/lib/mcp-client.ts
+++ b/packages/zai-cli/src/lib/mcp-client.ts
@@ -416,7 +416,7 @@ export class ZaiMcpClient {
       args.location = params.location;
     }
 
-    return this.callTool<WebSearchResult[]>(getMcpToolName('search', 'webSearchPrime'), args);
+    return this.callTool<WebSearchResult[]>(getMcpToolName('search', 'web_search_prime'), args);
   }
 
   // ============ Web Reader Methods ============
diff --git a/packages/zai-cli/tests/mcp-client.test.js b/packages/zai-cli/tests/mcp-client.test.js
new file mode 100644
index 0000000..fd7c7a8
--- /dev/null
+++ b/packages/zai-cli/tests/mcp-client.test.js
@@ -0,0 +1,29 @@
+import { test } from 'node:test';
+import assert from 'node:assert/strict';
+
+import { ZaiMcpClient } from '../dist/lib/mcp-client.js';
+
+test('webSearch calls the discovered snake-case search tool', async () => {
+  const client = new ZaiMcpClient({ enableVision: false });
+  let called;
+  client.callTool = async (toolName, args) => {
+    called = { toolName, args };
+    return [];
+  };
+
+  const result = await client.webSearch({
+    query: 'hello world',
+    recencyFilter: 'oneWeek',
+    location: 'us',
+  });
+
+  assert.deepEqual(result, []);
+  assert.deepEqual(called, {
+    toolName: 'zai.search.web_search_prime',
+    args: {
+      search_query: 'hello world',
+      search_recency_filter: 'oneWeek',
+      location: 'us',
+    },
+  });
+});
diff --git a/packages/zai-cli/tests/mcp-live.test.js b/packages/zai-cli/tests/mcp-live.test.js
index a24fdb9..13057f6 100644
--- a/packages/zai-cli/tests/mcp-live.test.js
+++ b/packages/zai-cli/tests/mcp-live.test.js
@@ -72,7 +72,7 @@ describeLive('MCP Live Tests', () => {
 
   it('includes expected core tools', () => {
     const expected = [
-      getMcpToolName('search', 'webSearchPrime'),
+      getMcpToolName('search', 'web_search_prime'),
       getMcpToolName('reader', 'webReader'),
       getMcpToolName('zread', 'search_doc'),
       getMcpToolName('zread', 'get_repo_structure'),
@@ -115,8 +115,8 @@ describeLive('MCP Live Tests', () => {
 
     const handlers = new Map();
 
-    handlers.set(getMcpToolName('search', 'webSearchPrime'), async () =>
-      client.callToolRaw(getMcpToolName('search', 'webSearchPrime'), {
+    handlers.set(getMcpToolName('search', 'web_search_prime'), async () =>
+      client.callToolRaw(getMcpToolName('search', 'web_search_prime'), {
         search_query: 'hello world',
         search_recency_filter: 'oneMonth',
         content_size: 'medium',
diff --git a/skills/zai-cli/references/advanced.md b/skills/zai-cli/references/advanced.md
index fb6d9d3..95b60f8 100644
--- a/skills/zai-cli/references/advanced.md
+++ b/skills/zai-cli/references/advanced.md
@@ -15,14 +15,14 @@ Use these when you need schemas or direct tool invocation.
 ```bash
 zai-cli tools --filter vision --full
 zai-cli tool zai.zread.search_doc --no-vision
-zai-cli call zai.search.webSearchPrime --json '{"search_query":"LLM tools"}'
+zai-cli call zai.search.web_search_prime --json '{"search_query":"LLM tools"}'
 ```
 
 ## Code Mode (TypeScript tool chains)
 
 ```bash
 zai-cli code run ./chain.ts
-zai-cli code eval "await call('zai.search.webSearchPrime', { search_query: 'zai cli' })"
+zai-cli code eval "await call('zai.search.web_search_prime', { search_query: 'zai cli' })"
 zai-cli code interfaces
 ```